"Patients with Marfan syndrome and related conditions (MASS phenotype, mitral valve prolapse syndrome, familial aortic dissection), Ehlers- Danlos syndrome and Stickler syndrome are being seen in the NHGRI Genetics Clinic. Clinical data collected include detailed information on skeletal, ocular and cardiovascular manifestations in each patient. Skin biopsies and blood samples for DNA analysis are being collected to enable correlation of clinical observations with specific biochemical and molecular findings. Additionally, clinical data will be analyzed to assess the validity of proposed new diagnostic criteria for Marfan syndrome. To date, mutations have been found in 8 families with Stickler syndrome. Extensive clinical information has been collected 79 patients with Ehlers-Danlos syndrome, 128 patients with Stickler syndrome, and 47 patients with Marfan syndrome. A new clinical phenotype, involving overlap between Marfan, Stickler and Ehlers-Danlos syndrome, has been recognized and is being characterized at the clinical and molecular levels. - Marfan syndrome, Ehlers-Danlos syndrome, Stickler syndrome, skeletal, ocular, cardiovascular - Human Subjects